The purpose of this application is to permit continuing support for the multidisciplinary investigative program in cardiovascular research at the Massachusetts General Hospital which aims to increase the basic understanding of cardiovascular function and to apply this knowledge to improving the prevention and management of cardiovascular diseases. This program involves the joint investigative talents and physical facilities of several important laboratories of the Departments of Medicine and Surgery: The Cardiac, Cardiac Catheterization, Cardiac Surgery, Cardiorenal, Hypertensive, Vascular Surgery and Pulmonary Units.